Alright, let's solve this problem step by step. We have 758255 and 13590, and we're subtracting the second number from the first.

Step 1: We'll start by subtracting the digit 0 and the borrow 0 from 5 in column 1 and get 5.
5 is the first digit of our result.

Step 2: We'll start by subtracting the digit 9 and the borrow 0 from 5 in column 2 and get -4.
We add -4 to 10 and get 6 as the next digit of the result.

Step 3: We'll start by subtracting the digit 5 and the borrow 1 from 2 in column 3 and get -4.
We add -4 to 10 and get 6 as the next digit of the result.

Step 4: We'll start by subtracting the digit 3 and the borrow 1 from 8 in column 4 and get 4.
4 is the next digit of our result.

Step 5: We'll start by subtracting the digit 1 and the borrow 0 from 5 in column 5 and get 4.
4 is the next digit of our result.

Step 6: We'll start by subtracting the digit 0 and the borrow 0 from 7 in column 6 and get 7.
7 is the next digit of our result.

So, 758255 - 13590 = 744665.